1. Field of the Invention
This invention relates to an electronic musical instrument which has several musical tone output sections, including a stereo output section, and more particularly to an electronic musical instrument having a pan control function which is capable of freely setting the image position of a generated musical tone.
2. Description of the Prior Art
The generally applied electronic musical instruments have a stereo output section designed to output the generated musical tone through the left and right channels (two channels), and the image position of the musical tone can be imparted to the outputted musical tone by adjusting the left and right channel output levels. Some electronic musical instruments can generate, simultaneously, two or more musical tones which have different tone colors. However, if the musical tones are generated at the same image position, the generated musical tones are less spread out. Therefore it has been proposed to shift the generation image position for each musical tone color (Japanese Patent Laid Open sho. 55-121492). This provides for a different image position of musical tone for each musical tone color, which makes it possible to create a sound field representing the ensemble if several musical tones are generated at the same time.
Nevertheless, the above-mentioned electronic musical instrument is able to set the sound output level of an analog musical tone signal independently through the left and right channels so as to provide the image position of musical tone. Therefore it can provide only the simple image position of musical tone and is unable to form the wider tone field specific to electronic musical instrument. Moreover, since image position fixing/moving of each musical tone color can not be freely selected, sufficient play effect cannot be obtained.
The above-mentioned electronic musical instrument has the disadvantage that because the image position of each musical tone color is fixed at a specific point and the image position of musical tone cannot be moved during tone generation, pan control is impossible. This makes it impossible to form a diversified tone field.
Electronic musical instruments, such as a synthesizer capable of moving the image position of musical tone along the previously set orbit, are available. However, the orbit is maintained merely for several seconds. Therefore, if tone is outputted continuously for a longer time, image position is not moved further, so that tone diversification is lost.
Moreover, the above-mentioned move is effective only while the tone generation instruction is valid (during key-on time). Consequently, while reverberation is generated, the image position is fixed, resulting in poor diversification of tone.
The above-mentioned electronic musical instrument, such as the synthesizer, is designed so that only pan control is performed with the aid of an operator, such as a wheel, in the previously set range. Therefore it cannot control movement of tone image in complicated fashion, and the tone image movement effect cannot be obtained directly by the state of playing.